Queries of data sources (e.g., SQL queries applied against a relational database, or in-memory queries against queryable local objects) are often written in a programming language, such as a source code for an application. A query written in one manner (e.g., a language-integrated query specified according to a programming language) is often processed by a query processing pipeline, which interfaces the query with the data source by parsing the query, translating it into a more easily managed form (e.g., SQL or an expression tree), serializing any objects or values used in the query, and sending the translated query to the data source. The query processing pipeline may also receive a query result, such as a result data set, and may present it to the rest of the application.